Pollution caused by single use plastic containers and packaging materials is epidemic, scarring the global landscape and threatening the health of ecosystems and the various life forms that inhabit them. Trash comes into contact with waterways and oceans in the form of bits of Styrofoam and expanded polystyrene (EPS) packaging, to-go containers, bottles, thin film bags and photo-degraded plastic pellets.
As this ocean trash accumulates it forms massive patches of highly concentrated plastic islands located at each of our oceans' gyres. Sunlight and waves cause floating plastics to break into increasingly smaller particles, but they never completely disappear or biodegrade. A single plastic microbead can be one million times more toxic than the water around it. Plastic particles act as sponges for waterborne contaminants such as pesticides. Fish, turtles and even whales eat plastic objects, which can sicken or kill them. Smaller ocean animals ingest tiny plastic particles and pass them on to us when we eat seafood.
Sustainable solutions for reducing plastic pollution are gaining momentum. However, continuing adoption requires these solutions to not only be good for the environment, but also competitive with plastics from both a performance and a cost standpoint. The present invention involves replacing plastics with revolutionary technologies in molded fiber without compromising product performance, within a competitive cost structure.
By way of brief background, molded paper pulp (molded fiber) has been used since the 1930s to make containers, trays and other packages, but experienced a decline in the 1970s after the introduction of plastic foam packaging. Paper pulp can be produced from old newsprint, corrugated boxes and other plant fibers. Today, molded pulp packaging is widely used for electronics, household goods, automotive parts and medical products, and as an edge/corner protector or pallet tray for shipping electronic and other fragile components. Molds are made by machining a metal tool in the shape of a mirror image of the finished package. Holes are drilled through the tool and then a screen is attached to its surface. The vacuum is drawn through the holes while the screen prevents the pulp from clogging the holes.
The two most common types of molded pulp are classified as Type 1 and Type 2. Type 1 is commonly used for support packaging applications with 3/16 inch (4.7 mm) to ½ inch (12.7 mm) walls. Type 1 molded pulp manufacturing, also known as “dry” manufacturing, uses a fiber slurry made from ground newsprint, kraft paper or other fibers dissolved in water. A mold mounted on a platen is dipped or submerged in the slurry and a vacuum is applied to the generally convex backside. The vacuum pulls the slurry onto the mold to form the shape of the package. While still under the vacuum, the mold is removed from the slurry tank, allowing the water to drain from the pulp. Air is then blown through the tool to eject the molded fiber piece. The part is typically deposited on a conveyor that moves through a drying oven.
Type 2 molded pulp manufacturing, also known as “wet” manufacturing, is typically used for packaging electronic equipment, cellular phones and household items with containers that have 0.02 inch (0.5 mm) to 0.06 inch (1.5 mm) walls. Type 2 molded pulp uses the same material and follows the same basic process as Type 1 manufacturing up the point where the vacuum pulls the slurry onto the mold. After this step, a transfer mold mates with the fiber package on the side opposite of the original mold, moves the formed “wet part” to a hot press, and compresses and dries the fiber material to increase density and provide a smooth external surface finish. See, for example, http://www.stratasys.com/solutions/additive-manufacturing/tooling/molded-fiber; http://www.keiding.com/molded-fiber/manufacturing-process/; Grenidea Technologies PTE Ltd. European Patent Publication Number EP 1492926 B1 published Apr. 11, 2007 and entitled “Improved Molded Fiber Manufacturing”; and http://afpackaging.com/thermoformed-fiber-molded-pulp/. The entire contents of all of the foregoing are hereby incorporated by this reference.
Fiber-based packaging products are biodegradable, compostable and, unlike plastics, do not migrate into the ocean. However, presently known fiber technologies are not well suited for use with meat and poultry containers, prepared food, produce, microwavable food containers, and lids for beverage containers such as hot coffee.
Methods and apparatus are thus needed which overcome the limitations of the prior art.
Various features and characteristics will also become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and this background section.